This invention relates to an emergency descending device, particularly to an emergency descending device having a pair of friction elements enveloped within a tubular housing, each friction element having a corrugated surface correspondingly engaged with that of the other, holding a life line therebetween, so as to carry a person along said life line at a low speed from a high position to a low position and provide a frictional force for controlling the rate of descent of a person.
In the past, various types of emergency descending devices have been proposed which can be used by a person in a high rise building to lower him/herself to the ground by paying out the line or cable from a reel.
Notwithstanding that many types of safety line reel-type emergency decending devices have been proposed, there has not really been any widely accepted use of such device. Part of the problem is that the earlier devices themselves are relatively expensive owing to complexity of structure and are not always foolproof in operation. For example, many such devices rely on a mechanical device to provide a retarding force or a frictional drag on the reel in order to slow the rate of descent of a person to a safe value. The existance of many mechanical elements in such a device for the purpose of providing a frictional force on the reel, complicate the entire structure of the emergency descending device. In addition, it is difficult to adjust such a mechanical device to provide the proper degree of friction. If there is too little friction, a person will drop too quickly risking bodily injury upon contact with the ground. If there is too much friction, the person cannot descend rapidly enough to escape from a dangerous situation.